Clock striking mechanism



July 3, 1951 A. w. SPURR 2,559,476

CLOCK STRIKING MECHANISM Filed May 25, 1949 jaderaior:

Mr: W. W

Patented July 3, 1951 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to a clock striking mechanism, and particularly to mechanism which will automatically disengage and lock after each strike. It is the object of the invention to provide a more positive acting and simplified mechanism for clocks which strike at designated times.

The invention will best be understood from the following description in conjunction with the accompanying drawings, in which:

Fig. 1 is a view in side elevation of said mechanism;

Fig. 2 is a top plan view;

Fig. 3 is a detail view corresponding to Fig. 1 and showing a different position for some of the parts, and

Fig. 4 is a detail View of one part.

As shown in the drawings, a clock frame I has pivoted thereto a lever 2 carrying an arm 3 and a support 4 for a bell 5 and its striker 6. A spring 1 urges lever 2 to the left in Fig. 1. The bell 5 is secured by screw 8 to a post 9. The free end of arm 3 bears on mechanism hereinafter described which urges it to the right in Fig. 1 against the force of spring I. Also carried by frame I is a shaft on which is mounted a disk H which rotates once each hour. A bushing l2 concentric with shaft l0 and separately driven carries a snail cam |3 which in this instance has three identical cam surfaces l4, l and I6 separated by abrupt drops l1, l8 and I9. This cam will make one complete revolution in twelve hours. The edge of snail cam 3 bears on the end of arm 3. The snail cam is designed according to the number of strikes desired at the end of each interval. The one illustrated is an eight bell cam, for four hour intervals. A one point snail would be used for an hourly strike.

Carried by shaft I0 is a gear wheel 20 having peripheral teeth 2 I. This gear revolves one complete revolution per minute. The important feature of this gear is that it makes a complete revolution in a much shorter space of time than the intervals between strikes.

Secured to or formed integrally with frame I is a frame extension 22 to which is pivotally secured a double arm shaft support 23, the opposite or free end of which carries a shaft 24 journalled therein. Shaft 24 carries a single point snail type cam 25 having peripheral gear teeth 26 which are adapted to mesh and at times do mesh with gear teeth 2|, which are directly below. Secured to the side of cam 25 is a count fan 21. The count fan determines the number of times the bell will be struck.

Secured to frame I below support 23 there is a flexible strut bar 28 having a lip 29 approximately at right angles thereto. When the strut bar is in normal position, the lip 29 lies under and supports the support 23 and thereby supports cam 25 over and out of contact with gear 20. When the strut is flexed laterally or displaced, the support 23 is permitted to drop until the teeth of cam 25 engage the teeth 2| of gear 20.

The disk I I, which rotates once an hour, carries at least one pin 30. It may carry more. In the present instance, it is also provided with a diametrically opposed pin 3|. These pins are carried, on rotation of the disk, against a trip lever 32 pivoted at 33. The lever 32, shaped generally like a bell crank, has an arm 34 which carries an angular extension 35 adapted to engage and laterally displace the strut 28.

The count fan 21, on reaching the position shown in Fig. 3, as determined by rotation of cam 25, extends beside and past a finger 36 on the striker 6. When the cam 25 turns, the ridges 31 of the count fan will cause displacement of the finger which, on release, is urged against the bell 5 by a spring 38.

In operation, the three point snail cam urges lever 2 to the right in Fig. 1 against spring 1, and so brings the finger 36 to a position in which it will be contacted by one or more of the ridges 31 of the count fan 21, the number of ridges contacting the finger increasing each time as the arm 3 approaches the high point of either of the cam elements l4-|6 which happens to be under it. The movement is relative; the bell mount can be stationary, and the support 23 be provided with means for moving it away from the bell as determined by the three point snail. The disk ll meanwhile rotates and brings one of the pins 30 or 3| into contact with the trip lever 32. When trip lever 32 displaces strut 28 the support 23 falls, and the cam teeth 26 engage and mesh with teeth 2| on gear 20. Thereafter rotation of gear 20 causes cam 25 to rotate, and as it rotates, its count fan comes into contact with the striker finger 35. According to the relative position of the striker and fan, one or more or all of the ridges 31 of the striker fan will cause the striker finger to move, and the striker 6 will hit the bell. Continued movement of the cam 25 will carry the shaft 24 upward, until the point of the snail is reached, 1. e. the greatest distance between shaft 24 and gear 20 is attained. Then the strut comes under the support 23, and the cam 25 is held out of contact with gear 20, which can rotate freely without causing the cam 25 to move the count fan into striker operating position. Then the next pin on the disk ll again causes tripping of the support 23, and the process is repeated at fixed intervals. Suitable choice of the number of pins on the disk H and of riser surfaces on snail cam l3 will cause the clock to strike chimes, hours, fractions of hours, or ships bells.

I claim:

1. In a clock for striking at fixed intervals, in combination, an eccentric cam, a count fan secured to said cam, a shaft for said cam, means for turning said cam to raise said shaft, and means for retaining said shaft in raised position.

2. In aclock having striking mechanism,incombination, a snail cam, a shaft for said cam, means for turning said cam and causing said cam by reason of said rotation to raise said shaft to maximum distance from said turning means, locking mechanism adapted to hold said shaft in elevated position after the maximum point on said cam has been reached, and means for releasing said locking mechanism to reengage said cam and turning means at predetermined intervals,

3. A clock for striking at fixed intervals having, in combination, a drive gear making one complete rotation during a small interval of time less than any interval between strikes, a snail cam with peripheral teeth adapted to mesh with the teeth of said gear and be turned thereby until the apex of said cam is reached, a cam shaft, pivoted means for holding said shaft, means for holding said pivoted means in raised position when said apex is reached, a trip lever for releasing said holding means, a disk making one complete rotation during a substantially longer interval than said drive gear, and means on said disk for actuating said releasing means.

4. A clock for striking at stated intervals having, in combination, a bell, a striker, a cam, a count fan on said cam for engaging a part of said striker, means for increasing and decreasing the relative distance between said fan and said striker, a wheel for rotating said cam to cause it to rise to a predetermined position above said wheel, means for locking said cam in said raised position out of contact with said wheel after the apex of said cam has been reached, and means for releasing said locking means to cause reengagement of said cam and said wheel.

ALLEN W. SPURR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 71,519 Lindon Nov. 26, 1867 84,709 Roberts Dec. 8, 1868 2,034,945 Haderman Mar. 24, 1936 

